The invention relates to a machine for cutting up, shredding and cleansing broad pieces or sheets of material and, in particular, to the machines that are employed in processes for salvaging broad pieces or sheets of plastic material such as, for example, worn sheets used to cover cultivated areas, or plastic sacks or similar, processes, that is to say, wherein the shredding of the said broad pieces or sheets and the cleansing thereof is envisaged, these operations generally being followed by others with which it is possible to reduce the shredded material to a granular state for it to then be sent to, for example, molding machines for the production of new broad pieces, sacks and/or sheets, or at any rate to be used again.